Lino Ferriani is the first jurist to investigate the antecedents of juvenile delinquents, by gathering notes not only regarding their parents, but also in regard to their own school standing (by consulting the teachers in the schools where these juvenile criminals received their education!). I have extracted from his volume on "Precocious and senile delinquency" the following statistics of the physico-moral condition of the parents:
| Convicted of crimes against property | 1,237 |
| Convicted of crimes against the person | 543 |
| Addicted to wine | 2,006 |
| Women leading meretricious lives | 581 |
| Doubtful reputation | 1,500 |
| Very bad reputation | 670 |
| Good reputation | 210 |
| Industrious | 1,888 |
| Semi-idle | 4,000 |
| Idle | 2,000 |
| Sentenced for drunkenness | 1,590 |
| Sentenced for offences against public morals | 240 |
| Alcoholics | 1,001 |
| Confined in lunatic asylums | 48 |
| Mothers deflowered before the age of 15 | 1,560 |
| Couples separated through fault of the husband | 59 |
| Couples separated through fault of the wife | 69 |
| Couples separated through fault of both parties | 135 |
Among these notes there is a numerical preponderance of idlers (the idle and semi-idle: degenerates are weaklings who cannot work and who shun work; their only form of work is crime, which is an attempt to reap the fruit of other people's industry) and alcoholism (addicted to wine, alcoholics, and those sentenced for drunkenness; this also is a stigma of degeneration: weaklings have recourse to alcohol, because it gives them an illusion of strength). Furthermore, the majority show, through crime and prostitution, that they belong to the class of social parasites.
In regard to the psycho-physical characteristics of juvenile offenders, Ferriani gives these principal notes:
And now we come to the most interesting part of all, namely, the notes taken by teachers where these children went to school.
Boys.—Age from ten to twelve years. Characteristic notes on 100 children in regard to bad conduct:
| Humiliating poorer companions | 2 |
| Absolute refusal to obey | 4 |
| Corrupting companions | 4 |
| Mutilating books of poor companions | 2 |
| Spirit of rebellion | 1 |
| Malicious and headstrong | 1 |
| Resentful of routine | 1 |
| Stealing food at expense of companions | 6 |
| Abnormally spiteful | 4 |
| Impertinent answers | 7 |
| Proud of inventing misdeeds | 2 |
| Stealing from companions and teacher (school stationary, etc.) | 10 |
| Calumniating companions | 6 |
| Desire to play the spy | 8 |
| Obscene writings in toilet room | 2 |
| Obscene writings in copy-books | 6 |
| Obscene actions in the school-room | 9 |
| Obscene writings on the benches | 3 |
| Violence with a weapon (pen-knife) | 2 |
| Bullying smaller boys | 12 |
| Feigning loss of speech for a month, to avoid reciting lessons | 1 |
| Blaspheming | 1 |
| Afraid of everything and savagely vindictive | 1 |
| Frequently absent from school, to play games of chance | 3 |
| Spirit of destruction | 1 |
| Spirit of contradiction | 1 |
Girls.—Age from ten to twelve years. Characteristic notes on 50 children in regard to bad conduct: